they are reliable depends on who puts it together and how i had no problems i just want more torque so i took it apart and i am rebuilding it make sure the pistons are the phk i think thats right then instead of 9.1:1 youll have 10.1:1 the b20bs are the same if it is a jdm block just depends on what year it was made if its 98+ its basically a b20z gsr head would be better u get .2 - .3 more compression and they are less prone for detonation and as long as you get the GE lsvtec kit there is less chances for oil leaks and more reliable